At an informal high school group reunion after the end of US warfare in Vietnam, and later when I was talking to someone who'd been in the CBR biz during the 'Nam years (that's "Chemical, Biological, and Radiological warfare") — I was told that despite my training in microbiology I would not have gone to Fort Detrick to make new and better bubonic plague had I been drafted but would've been infantry in 'Nam itself, probably with a promising (brief?) career as a tunnel rat. Still, I considered submitting to conscription and trying to get to Detrick as opposed to other options, in part on the ethical grounds that if white phosphorous and napalm were okay, the threat of "germ warfare" wasn't all that out of line. (Bigger part was my not being keen on the outdoor life, plus some idea from ROTC about what infantry grunts do and can suffer.)
And from there I came to the question raised by a student in the CBR course I took of why the international conventions prohibiting CBR have mostly held, whereas there was no similar success with long-dead conventions against submarines' blowing ships out of the water without warning, or fleets of aircraft bombing cities and starting fire-storms that would incinerate civilians by the thousands.
HINT: Check out probable casualties by kilogram of various lethal stuff. (I found the figures in the 1970 ENCYCLOPAEDIA BRITANNICA, and yes, Virginia, there are people who work out tables of such things, even as human beings before and during World War I worked out gunnery tables for rolling barrages that maximized enemy casualties while minimizing one's own, including casualties from "friendly fire.")
And from there I came to the conviction that we should support the international prohibitions against CBR on the grounds that any rules limiting weapons were better than none — but come off it! Biological warfare is inherently dangerous to the human species and therefore should be out of bounds, but gas warfare is ethically no worse than various ways of burning people with other kinds of chemicals, or using mines or cluster munitions to maim them. (And Virginia: There were people who worked out that maiming enemies is more effective than killing them. Do the math on how many people are taken out of military action by a death as opposed to severe bodily harm, and the psychology of what people — young men and older boys most specifically — most fear.)
And so I can't get too excited over "Red Lines" crossed in Syria with gas warfare and tend to believe that Assad et al. wouldn't use gas so long as they can deliver more effective agents to kill, wound, maim, and/or traumatized enemies and/or perceived enemies and/or people in the general vicinity thereof. (See "collateral damage" as the euphemism of choice for blowing the shit out of said people in the general vicinity. Or burning them. Well, etc.: There are lots of different munitions.)
And so I think we should definitely consider the argument by the usually reliable Seymour Hersh that the Syrians did not use Sarin gas and, therefore, weren't in line for the missile attack ordered by US President Donald Trump.
Please do see the article, and please try to help it go viral. Whether he's right or wrong in this case, the article and where it was and was not published raises important issues.
Hersh article in Die Welt: Here
Note: The war wonks went from "CBR" to "NBC": Nuclear, Biological, and Chemical" warfare, which helped allow the G. W. Bush administration to conflate poison gas with hydrogen bombs as "WMD" (which has its own labelling issues) and now. for homeland security purposes, "CBRNE": Chemical, Biological, Radiological, Nuclear, and Explosives.